There are no acceptable prior art heat stress and cold weather exposure relief systems for individuals, such as soldiers, operating in hot and cold environments for extended periods of time. Desert conditions for example often place individuals in a heat stress environment during the daylight hours and in severe cold during the nighttime. Heat stress can result in sweating, fatigue, dehydration, dizziness, hot skin temperature, muscle weakness, increased heart rate, heat rash, fainting, injuries, weight loss, heat stroke, heat exhaustion, and even death. The risk of heat stress is even greater for those wearing nuclear, biological and chemical (NBC) protective clothing, as well as aircrew personnel wearing flight gear. Cold weather exposure can cause discomfort; pain; numbness; cardiac, circulatory and respiratory problems; diminished muscle function and performance; frostbite, and hypothermia which can lead to unconsciousness and death.
While a portable, lightweight, low power, personal cooling and heating system can reduce heat stress, reduce the adverse effects of cold exposure, improve performance, and reduce water consumption, current active and passive cooling systems fall short of meeting the minimum requirements for an optimal system.
Active personal cooling devices are well know in the prior art. Also active personal heating systems are known in the prior art. The prior art, however, seems to be devoid of a combination cooling and heating system functioning with any significant efficiency over longer periods of time. The current active cooling and heating systems, however, are too heavy, bulky, inefficient, and are effective for only a limited amount of time. These devices also consume too much power and use potentially dangerous materials such as lithium sulfur dioxide batteries or R134 a refrigerant. Passive cooling and heating systems use packets containing phase change chemicals, water or gel that require refrigeration, freezing or heating before use are not suitable to meet the needs of a user where refrigeration, freezing or heating of the passive cooling or heating components are unavailable such as in military field operations in hot, cold or combined hot and cold climatic conditions. The prior art active cooling and heating systems that have been developed, include:                1. U.S. Army PICS (Personal Ice-Cooling System) Problem: This system uses packed ice. The ice must be changed every 30 minutes, and users such as pilots and field deployed soldiers may not have access to ice to replenish the system.        2. U.S. Army PVCS (Portable Vapor Compression Cooling System) Problems: The total system is much too heavy (27 pounds); uses potentially dangerous lithium sulphur dioxide batteries, can't use vapor compression on non-level surfaces such as ships; R134a containers can rupture in high temperatures, exposure to liquid or vapor refrigerant can cause frostbite, high exposure to fumes can cause central nervous system depression, irregular heartbeat and suffocation.        3. U.S. Army ALMCs (Advanced Lightweight Microclimate Cooling System) Problems: A voltage delay phenomenon can cause lithium sulphur dioxide batteries not to start especially after storage; the batteries can vent toxic sulphur dioxide gas that can cause respiratory distress and burns if there is accidental electrical charging, puncturing or application of heat. The batteries are not rechargeable, cannot be exposed to high temperatures, are very reactive with water and cannot be opened, punctured or crushed.        4. IMCC (Integrated Mesoscopic Cooling Circuits) (DARPA) Problem: Insufficient cooling.        5. Absorption/Evaporative Cooling (DARPA). Problem: According to Roger Masadi at the Natick Soldier Center, typical desiccants only adsorb about 20 percent of their weight in water, and the cooling density is approximately the same as ice.        6. NASA and U.S. Air Force (APECS) Aircrew Personal Environmental Control System Problem: This system is too bulky for infantry soldiers.        7. Life Enhancement Technologies Problem: The ice water mixture for the cooling unit must be replenished.        
While each of these prior art personal cooling and heating systems may fulfill their respective particular objectives and requirements, and are most likely quite functional for their intended purposes, it will be noticed that none of the prior art cited disclose an apparatus and/or method that is portable, rugged, and lightweight and that can be used in any orientation or used as a belt-mounted system or a backpack, to meet the operational requirements of the user. Also, the prior art cannot provide several continuous hours of operation at a rate of 700 to 1000 BTUs of adjustable cooling or heating per hour.
As such, there apparently still exists the need for new and improved personal cooling and heating system to maximize the benefits to the user and minimize the risks of injury from its use.
In this respect, the present invention disclosed herein substantially corrects these problems and fulfills the need for such a device.